Update Ring dependency

Author: weavejester

project.clj

@@ -4,7 +4,7 @@
   :license {:name "The MIT License"
             :url "http://opensource.org/licenses/MIT"}
   :dependencies [[org.clojure/clojure "1.9.0"]
-                 [ring/ring-core "1.12.1"]]
+                 [ring/ring-core "1.13.0"]]
   :plugins [[lein-codox "0.10.8"]]
   :codox {:output-path "codox"
           :source-uri "http://github.com/ring-clojure/ring-websocket-middleware/blob/{version}/{filepath}#L{line}"})